1. Field of the Invention
The present invention relates to a process for dispersing, comminuting or deagglomerating and classifying solids and to a classifier jet mill for carrying out these operations.
2. Description of the Prior Art
There are numerous known ways and machines for carrying out the abovementioned operations.
The choice of which process or equipment to use depends on various criteria, for example the particle size and nature of the solids.
Existing processes and apparatus are described in detail in the technical literature and makers' documentation.
For instance, in the text book by Vauck/Muller, Grundoperationen chemischer Verfahrenstechnik, 6th edition, the section on size reduction deals with:
(a) comminution of solids by means of a closed cycle (page 228), and PA0 (b) comminution of solids by means of ball mills, impact and centrifugal mills and jet mills (page 247 et seq.). PA0 1. selective comminution of the easily dispersible portions without product damage, PA0 2. specific control of the length of time and the stress conditions under which the solids are resident in the dispersing space; that is, continuous and adjustable discharge of the difficult-to-disperse constituents or foreign substances from the dispersing space, PA0 3. no rotating parts to avoid explosion hazards.
The same text book describes various spiral flow classifiers in the section on classifying (see page 297 et seq.).
Brochure 23/1d from Alpine AG, Augsburg, describes a classifier mill where the combined grinding and classification of the crude and end products is obtained by means of one machine unit.
However, the prior art processes and machines have various disadvantages, for example too much oversize and hence loss of material, damage to the readily dispersible portions of the product due to the high energy input required for comminution, or the need for the expensive inert gas procedure or similarly expensive pressure-resistant apparatus with explosive products.